Gas-exhauster.



N0. 819,830. PATENTED MAY 8, 1906 J. T. WILKIN.

GAS EXHAUSTER. APPLICATION FILED 1,111.30, 1905.

murals sra'ras PATEN hhlCE.

Specification of Letters Patent.

Patented ma 8,1908.

Application filed January 30, 1905. Serial No. 248,214.

In the use of exhausters of the two-impch ler type for pumping gases, especially illumimating and fuel gases, there is unavoidabl some leakage between the ends of the impellers and the inclosing casing, and it is found in practice that this leakage passes to the stuffing-boxes around the shafts at their points of emergence from the casing and that it produces a hardening of the aching of such character as to render it very ifficult to keep these stut'dngboxcstight and lubricated.

l is-the operation or such machines the cannot ordinarily be stopped to be repackeri, and as any attempt to re ack the stuffin box during operation results in considerable temporar leakage and a consequent almost unbearab e stench it is not unusual to find that the o erator continues to ti hten up the packingg and even after the padlring has be come hardened, so that the hardened packing 1s forced into the shaft, and oonsequentl cuts it very seriously and requires too much power to operate it.

The object of my present invention is to produce a sim le construction by means of whlch any lea urge between the ends of the impellers and the end walls of the casing will be by-passed away from the aching-glands, preferably into the suction si e, so that there vnll be no tendency for the gas to pass to the pack ng. As, a consequence I am able to provide the packing-glen ds with gravity oiling devices.

The accompanying drawings illustrate my said invention.

Figure 1 is a side elevation, in partial axial section, of a pump of the class described provided with m improvement. Fig. 2 is an elevation of the inside of a part of an end late; Fig. 3, a detail axial section on an eniarged scale, and Fig. at a section on line 4 4 of Fig. 1.

In the drawings, 10 indicates the semicylindrical sides, 11 11 the end plates, and 12 12 the top and bottom plates, of a two-impeller rotary exhauster of any ordinary type, such as may be commonly found in the market.

Mounted in the casing thus formed are-two coacting two-lobe impelle'rs 13 13, which are carried by shafts 14 14, which extend throu h suitable packinglands 15, formed in t s end plates 11, an are journaled in suitable bearings 16. All of the construction thus far described is common and ordinary, and the two impellers coact together to form when rotated in the direction indicated by the arrows in Fig. 4 a suction-space 17 and a pressure-space 18.

The ends of the impellers fit closely against the inner face of the end plates 11, and the leakage occurs between these parts, passing from the pressure side toward the shaft. This pressure is sufficient to force the gas outward into the packing-gland 15, so that as a consequence it has heretofore been'impossible to provide any system of gravityoiling for this packing-box.

My invention consists of a by-pass chamber between the ends, of the impellers and the adjacent end plates and connecting this chamber either with the suction side 17 of the pump, as shown in the drawings, or connecting said chamber to the outside of the casing.

In the present drawings I have-shown this by-pass c amber 20 as formed by an annular groove formed in the hub of the impeller around the shaft 14. The chamber communicates with a groove 21, formed in the lower side of the inner face of the plate 11 and extending downward to a point where it is continuously open into the suction-chamber 17.

This is probably the most advisable and practical arrangement, and I consider it desirable-that the chamber 20 be at all times open into the suction-chamber; but this is not necessarily so, as it may be of such len th as to be only uncovered twice in eachrevo 11- tion of each impeller by the passage of the slot.

there IS a. considerable residuum from the as deposited in the form of a sticky mass, an it In the operation of machines of this type lobes of the impeller over and away from the I is therefore desirable that some means be provided for readily cleaning the byass chamber. In order to do this, 1 p1 ovi e a erforation 22 in the end plate 11 which registers with the annulus 20, and this perforation is closed by a screwlug 23, the arrangement being such that h withdrawing the screw-plug 23 during the operation of the pump a scra er may be inserted to scrape the walls of t e annular groove 20 as the impeller rotates.

In operation any gas which is forced from the pressure side inward toward the shaft between the" end of the impeller and the end plate will and fromence pass freely into the suctionchamber 17, through the groove 21, as this will be the line. f least resistance, and the leakage will not, therefore, pass farther inward toward the shaft and homthence outwardinto the packing 15 for the reason that the packing w1ll be under atmospheric pressure, while the pressure in chamber 17 will be somewhat less. As a consequence by this arrangement I find it possibleto provide the seeking 15, with an ordinary gravity oiling evice 25, so that the packing may be kept continuously moist, thus insur ing a tight joint and good lubrication.

I claim as my invention-- 1. In an exhauster of the two-impeller type, a by-pass chamber formed between the end of an impeller and the) adjacent end plate of the casing and communicating with he suction side. 1

2. In an exhauster of the two-impeller type, a by-pass chamber formed between the end of an impeller and c the adjacent end plate of the casing and he suction side, a stufling-box around the Shaft, and an oiling device therefor.

3. An exhauster having an inclosing casing and a air of lobed impellers rotatably mounted t erein] and having. an annular groove formed inthe end of an impeller adfioent the end plate, and a passage leading groove to the suction side of. the ex' hauster.

4. In an exhauster having an inclosingcasing and a' air of lobed impellers rotatably mounted t rein and having an annular groove formed in the end of the im eller adacent each end plate, a passage lea ing from each groove to the suctioii side of. the exhauster, a stuffing-box around the shaft of each impeller, and an oiling device therefor.

5.. In an exhauster having an inclosing casing and a ir of lobed impellers rotatably mounted t erein and having an annular groove formed in the end of the im eller adacent each end plate, a passage lea ing from each groove to the suction side of the exhauster, and means permitting access to each annular groove through the casing.

6. In an exhauster of the two impeller type, a by-pass chamber formed between the end of the impeller and an adjacent end plate of the casing, said by-pass chamber opening to a region of less pressure than that in the pressure side.

7. In an exhauster having an inclosing casass into the annular groove 20.

communicating, with ing-chamber u ing, and a lobed impeler rotatably mounted therein and having an annular groove formed in the end of the impeller adjacent the end plate, a stuffing-box around the shaft of the impeller, and a passage leading from the said annular groove to a region of less pressure than that in the pressure side.

8. In a device of the class described, the, combination, with a suitable inclosing cas- I ing of a air of coacting lobed'impellers mounted tiierein and separating the casingchamber into two sides, and a by-pass chamber formed between the end of an impeller and the adjacent end .plate of the casing and communicating with the casing chamber upon one side of the impellers.

' 9. In a device of the class described, the combination, with a suitable inclosing casing, of a air of coacting lobed impellers mountd t erein and separating the casingchamber into two sides, and a by-pass chamber formed between each end of each impeller and the adjacent end plate of the casing, all of said bypass chambers communicating with the casing-chamber upon one side only of the impellers.

10. In a device of-the class described, the

combination, with a suitable inclosing casing, of a air of coacting lobed impellers mounted t erein and separating the casingchamber into two sides, shafts carrying said lobed impellers projecting through the end plates of the casing, and an annular by-pass chamber formed between each end of each impeller and the adjacent'end late and surrounding the adjacent shaft, al of said bypass chambers communicating withrthe casing-chamber upon one side only of the impelers.

- 11. In a device of the class described, the mo combination,- with a suitable inclosing casing, of a air of coacting lobed impellers mounted t erein and separating the casingchamber into two sides, shafts carrying said I lobed impellers projecting through the end 1 plates of the casing, and an annular by-pass chamber formed between each end of each impeller and the adjacent end plate and surrounding the adjacent shaft, all of said bypass chambers communicating with the casno on one side only of the impellei-s, a stuflingox around each shaft, and an oiling device therefor.

In Witness whereof I have hereunto set M y I hand and seal at Connersville, Indiana, this 26th day of January, A. D. 1905.

. JOHN T. WILKIN. [n s] Witnesses:

HYATT L. Fnosr, RUBY M. Navn. 

